1. Field of the Invention
The present invention relates to new industrial processes for the preparation of vitamin K derivatives, which play an important role in the vital body as hematostatic vitamins, coenzyme Q derivatives, which are useful as therapeutic agents for ischemic heart diseases such as congestive heart failure, and the like, and intermediates useful for the preparation thereof.
2. Description of the Background Art
It has heretofore been known that quinone derivatives can be prepared by reacting 2-methyl-1,4-naphthoquinone (common name: menadione; in the following chemical reaction formula, R.sup.1 and R.sup.2 form a benzene ring), 2,3-dimethoxy-5-methylbenzoquinone (in the following chemical reaction formula, R.sup.1 =R.sup.2 =a methoxy group), or the like with an allyl halide derivative in accordance with the Friedel-Crafts reaction as shown by the following chemical reaction formula: ##STR2## wherein R.sup.1 and R.sup.2 are identical with or different from each other and mean individually a lower alkyl or lower alkoxy group, or may form an aromatic ring together, n stands for 0 or an integer of 1-9, and a linkage ------ is a single or double bond.
Besides, Japanese Patent Application Laid-Open (KOKAI) No. 56935/1985 discloses a process for preparing a quinone derivative by forming 1,4,4.sub.a .alpha.e,9.sub.a -tetrahydro-9.sub.a .alpha.-methyl-1.alpha.,4.alpha.-alkenyl-1 .alpha.,4.alpha.-methanoanthraquinone from 2-methyl-1,4-naphthoquinone and cyclopentadiene, reacting this product with an allyl halide derivative into a 1,4,4.sub.a .alpha.,9.sub.a -tetrahydro-9.sub.a .alpha.-methyl-4.sub.a .alpha.-alkenyl-1.alpha., 4.alpha.-methanoanthraquinone, and then subjecting the thus-obtained product to a Retro Dieis-Alder reaction.
In the conventional processes for preparing quinone derivatives, 2-methyl-1,4-naphthoquinone, 2,3-dimethoxy-5-methylbenzoquinone or the like has been used as a starting material as shown in the above chemical reaction formula. However, these compounds have been extremely expensive and hence difficult to obtain in a great amount on an industrial scale. Further, quinone derivatives produced by conducting the Friedel-Crafts reaction undergo geometric isomerization on the allyl group. Therefore, the final product is provided as a mixture of cis (Z) and trans (E) isomers. In addition, they are very difficult to separate from each other to purify them because their physicochemical properties are similar to each other. Accordingly, this process has not been said to be an industrially or economically satisfactory process.
On the other hand, the process disclosed in Japanese Patent Application Laid-Open (KOKAI) No. 56935/1985 can improve the disadvantage that the geometric isomers are formed, but has remained using 2-methyl-1,4-naphthoquinone as a starting material. Therefore, a problem has remained unsolved from the viewpoint of obtaining the starting material.
In addition, the process disclosed in Japanese Patent Application Laid-Open (KOKAI) No. 56935/1985 requires a strong base such as a metal amide, lithium dialkylamide or alkali metal t-butyrate for the reaction of 1,4,4.sub.a .alpha.,9.sub.a -tetrahydro-9.sub.a .alpha.-methyl-1.alpha.,4.alpha.-methanoanthraquinone or the like with an allyl halide derivative. However, these strong bases are materials difficult to industrially handle in a great amount from the viewpoint of flammability, corrosiveness, decomposition behavior due to moisture absorption, toxicity, shelf stability and the like.
1,4,4.sub.a .alpha.,9.sub.a -Tetrahydro-9.sub.a .alpha.-methyl-1.alpha.,4.alpha.-methanoanthraquinone or the like, which is a starting material in the above publication, is obtained by the Dieis-Alder reaction of 2-methyl-1,4-naphthoquinone, 2,3-dimethoxy-5-methylbenzoquinone or the like with cyclopentadiene. However, this addition reaction is greatly affected by the steric hindrance of the methyl group attached to an .alpha. position of the quinone. Therefore, the reaction is extremely slow, and it takes four long days to complete the reaction as described in Examples of the above publication. Such a process has hence been disadvantageous from the industrial viewpoint.
As described above, the disadvantage of forming the geometric isomers, the problem from the viewpoint of obtaining starting materials, the difficulty of handling the bases, or the time problem involved in the preparation of the starting material has not been yet solved in the conventionally-known processes. Therefore, such processes all have been insufficient for industrial process. With such a background, there has been demand for development of an industrially excellent preparation process for quinone derivatives, by which an intended quinone derivative can be prepared from cheap and easily available starting materials with good operating simplicity for a short period of time without forming any geometric isomer.